1. Technical Field
The disclosure relates generally to silicidation processing, and more particularly, to surface cleaning prior to siliciding using a sacrificial getter layer.
2. Background Art
Silicide is an alloy of a metal, e.g., nickel (Ni), and silicon (Si) that typically provides quality electrical contact between a structure in a silicon substrate and a metal contact thereto. Surface cleaning and preparation is required for silicide contact formation. During formation of the structure in the silicon substrate, residual materials left over can block the formation of silicide and cause device and yield degradation. Typically, several cleaning steps have been employed for pre-cleaning, which includes wet and dry cleaning procedures. In order to achieve high process and product yields, significant amounts of overreach into adjacent gate spacers and isolation regions is required during the wet and dry cleaning procedures. For 32 nanometer and smaller technology nodes, in order to achieve appropriate yields, the amount of pre-cleaning used is reduced in order to preserve spacer and shallow trench isolation (STI) oxide, which may not result in all contaminants being adequately removed.